The present invention relates generally to loaded pallet handling systems and, more particularly, to a system and method for applying a printed label to a loaded pallet that identifies the goods loaded onto the pallet.
Pallets are used to store and transport loads of a vast range of goods. For example, a pallet can be used to transport boxes of goods that have been stacked and shrink-wrapped or otherwise secured upon the pallet from a manufacturer to a point of sale. Proper identification of the goods loaded onto the pallet, and of the loaded pallet itself, is critical to assist in proper routing of the loaded pallet within a warehouse or distribution center, and also at a customer""s facility.
In the past, printed labels have been applied to loaded pallets that contain label information pertinent to the product or goods loaded onto the pallet, such as the product identification code, pallet identification code, quantity, lot number, customer or order identification data and routing codes. These printed labels have been either affixed to the loaded pallet by hand or, more recently, by semi-automated pallet labeler systems that are capable of applying one or more printed labels to the loaded pallets as the loaded pallets are transported intermittently on a conveyor past the pallet labeler system. Proper positioning of the label on the loaded pallet is important to ensure that the label is not affixed in an irregular area of the loaded pallet or at a position that cannot be read by a scanner or other device that controls routing of the loaded pallet in an automated warehouse or distribution center environment.
More particularly, pallet labeler systems have been developed in the past that are capable of printing labels with pre-selected pallet and/or product identification information and applying printed labels to one side of a loaded pallet at one or more predetermined positions, such as upper and lower label positions on the same pallet load. Prior pallet labeler systems having included a label applicator mechanism that is capable of receiving printed labels from a label printer and transporting the printed labels toward the loaded pallet for applying the printed labels thereto at the predetermined label positions. Positioning of the label applicator mechanism relative to the loaded pallet has been accomplished through a ball screw drive mechanism having electro-mechanical limit switches that set the predetermined upper and lower label positions.
For example, known pallet labeler systems have included a label applicator mechanism that is movable in upward and downward vertical directions under the control of the ball screw drive mechanism. The label applicator mechanism is moved by the ball screw mechanism so as to apply printed labels to the loaded pallet at the predetermined upper and lower label positions. The electro-mechanical limit switches are manually adjusted and set in the ball screw drive mechanism so that the label applicator mechanism will move and stop at the upper and lower label positions when the respective upper and lower limit switches are actuated. However, when label positions are to be changed, such as when a loaded pallet having a different configuration is to be labeled, the limit switches must be manually adjusted and set according to the new label positions. This is not only time consuming and cumbersome, but also severely limits the ability of the pallet labeler system to efficiently label a wide range of loaded pallets having many different predetermined label positions.
In known pallet labeler systems, the printed label is applied to the loaded pallet through a tamp pad that is pivotally mounted on a forward end of an applicator arm. The tamp pad is positioned to receive a printed label from the label printer, and to transport the printed label toward the loaded pallet to apply the label thereto. A fiber optic sensor mounted on the tamp pad senses the loaded pallet and is used to retract the tamp pad from the loaded pallet after the printed label has been applied. However, the fiber optic sensor used to sense the loaded pallet is prone to cause the tamp pad to retract before the label has been completely applied to the loaded pallet. This may be caused by reflections from the shrink-wrap material or in situations where the shrink-wrap is loosely spaced from the underlying goods. In either case, the fiber optic sensor improperly causes the tamp pad to retract before sufficient contact between the label and the loaded pallet has occurred.
The tamp pad in known pallet labeler system includes apertures and bores that are in fluid communication with a vacuum source fluidly connected to the tamp pad through a vacuum hose. An air assist tube emits pressurized air toward the printed label as it separates from its backing web at the label printer to move the label into engagement with the tamp pad. Vacuum pressure is applied to the tamp pad to hold the printed label thereto as the tamp pad is extended toward the loaded pallet to apply the label. However, in the past, the pressurized air source connected to the air assist tube and the vacuum source connected to the tamp pad have each run continuously throughout the entire label printing and application process. As a result, the apertures in the tamp pad tend to become clogged over time with dust and other contaminants and the tamp pad eventually loses its ability to reliably hold the printed labels. Further, a large amount of air is used in the label printing and application process.
Thus, there is a need for a pallet labeler system that is capable of efficiently applying printed labels to a wide range of loaded pallets having many different predetermined label positions.
There is also a need for a pallet labeler system that reliably applies printed labels to loaded pallets with sufficient contact to ensure the printed label is held thereto.
There is yet also a need for a pallet labeler system that uses pressurized air and vacuum sources efficiently during the entire label printing and application process.
The present invention overcomes the foregoing and other shortcomings and drawbacks of pallet labeler systems and methods heretofore known. While the invention will be described in connection with certain embodiments, it will be understood that the invention is not limited to these embodiments. On the contrary, the invention includes all alternatives, modifications and equivalents as may be included within the spirit and scope of the present invention.
In accordance with the principles of the present invention, a pallet labeler system is provided that is capable of efficiently and reliably applying printed labels to a loaded pallet at a multiplicity of predetermined label positions. The pallet labeler system includes a label printer that is capable of printing pre-selected pallet and/or product identification information on a label. A label applicator mechanism is operatively connected to the label printer for receiving a printed label from the label printer. The label applicator mechanism is mounted for movement relative to the loaded pallet and includes a pivotally mounted tamp pad that is capable of holding and transporting a printed label toward loaded pallet for applying the printed label thereto at a predetermined label position.
In accordance with one aspect of the present invention, the pallet labeler station includes a rack and pinion drive mechanism for variably moving the label applicator mechanism so as to apply the printed label to the loaded pallet at the predetermined label position. A programmable control is operatively coupled to the rack and pinion drive mechanism and is capable of receiving label position data that defines the predetermined label positions. The label position data is preferably received either from an upstream loaded pallet handling station or is obtained from a look-up table. The programmable control, in response to receiving the label position data, causes the rack and pinion drive mechanism to move the label applicator mechanism so as to apply the printed label to the loaded pallet at the predetermined positions defined by the label position data.
In accordance with another aspect of the present invention, the pallet labeler system includes a vacuum source fluidly connected to the tamp pad for holding the printed label thereto during transport of the printed label toward the loaded pallet. An air assist tube is connected to a source of pressurized air and is provided to emit pressurized air jets that move the printed label toward the tamp pad. In accordance with the principles of the present invention, the pressurized air jets are turned on when the printed label begins to separate from its backing web. As the label is being separated from the backing web, the vacuum supplied to the tamp pad is turned off until the label has generally completely separated from the backing web. When generally complete separation of the label from the backing web has occurred, vacuum pressure is then applied to the tamp pad to hold the label thereto and the pressurized air jets from the air assist tube are turned off.
In accordance with yet another aspect of the present invention, the tamp pad includes a sensor that is capable of detecting movement of the tamp pad from a xe2x80x9ctransport positionxe2x80x9d, wherein the tamp pad is carried at an angle relative to the side of the loaded pallet, to an xe2x80x9capplication positionxe2x80x9d, wherein the tamp pad is generally parallel to the side of the loaded pallet. The tamp pad moves to the xe2x80x9capplication positionxe2x80x9d upon contact with the loaded pallet. Upon detecting the xe2x80x9capplication positionxe2x80x9d of the tamp pad, the sensor is operable to cause the tamp pad to retract away from the loaded pallet and toward a xe2x80x9chome positionxe2x80x9d.
The pallet labeler system of the present invention has the particular advantage of applying printed labels to a loaded pallet at a multiplicity of label positions. The rack and pinion drive mechanism provides variable movement of the label applicator mechanism relative to the loaded pallet. The predetermined label positions are defined in software by the label position data that is either received from an upstream loaded pallet handling station or is obtained from a look-up table. The combination of the pre-programmed label position data and rack and pinion drive mechanism provide for accurate, repeatable and efficient application of printed labels to pallet loads at a multiplicity of variable label positions. The proximity sensor associated with the tamp pad ensures that sufficient contact is made between the printed label and the loaded pallet before the tamp pad is retracted. Further, the efficient use and control of the pressurized air and vacuum sources reduces the amount of air required for the label printing and application process and significantly reduces likelihood that the apertures formed in the tamp pad will become clogged with dust and other contaminants over time.